This invention relates generally to thermosetting resin-hardener filling or coating systems and more particularly concerns such systems which require fast curing times and accordingly where the working time of the resin is quite short and therefore extremely sensitive to ambient temperature.
The invention applies to at least two package systems where the resin and the hardener are in separate packages and are not intermixed to form a filling compound until just prior to being applied to a working area.
The working life or useful life of a compound such as a thermosetting resin-hardener intermix can be measured from the point at which the resin is first intermixed with its hardener or catalyst until it reaches a state of no longer being workable or applicable to its end use. In some instances, the working life may be different from the pot life when the compound is allowed to sit for a while in the container before spreading on the working area for filling or coating. In either case, as time passes the compound becomes thicker until it becomes unworkable, in other words it becomes so thick that it begins to crumble or cannot be evenly applied.
The types of filling or coating compounds that the invention is concerned with are formulated for applications in which an extremely fast curing rate and accordingly fast set time is necessary, such as in areas where there is only a limited time before the surface must be ready for foot traffic, truck or wear. Normally these applications are in places where heat or temperature cannot be controlled or cover such large areas that temperature control is infeasible. Consequently, the curing compound is subject to the ambient temperature which may be the indoor room temperature or the outdoor temperature, both of which may vary during storage, use and curing of the blends or compound.
As is well known, small changes in temperature can raise havoc in the reaction rate of many chemical systems. Thus, for a change of temperature of 10.degree.C. the rate of reaction is usually doubled or halved depending on whether there is an increase or decrease in temperature respectively. Moreover, seasonal temperature changes make a system which gives desired working and curing times in summer take too long to cure in winter; similarly a system with an adequate working time in winter can have an undesirably short working time in summer.
Accordingly, a method and a set of products are presented in the instant invention which allow a user to choose an appropriate set of resins, diluents, and hardeners according to the ambient temperature at time of application of the compound. In the preferred embodiment a single resin diluent blend is utilized all year round or for different ambient temperatures, and a hardener blend is selected according to the ambient temperature. Thus one hardener is used for high temperatures and another hardener is used for low temperatures. However, other systems may be designed using the principles of the invention to vary any of the components of the system so that different resins or diluents can be utilized. Resins, diluents and hardeners can be selected to achieve the proper working and cure times for any critical ambient temperature range.